GNS3 and VirtualBox

Before you run your virtual network under GNS3, make sure you:

GNS3 overwrites the interface names that are configured in VirtualBox. If you want to use the VMs in VirtualBox and GNS3, consider cloning them first.

To run your virtual network under GNS3:

  1. Start GNS3.

  2. Select GNS3 > Preferences. The Preferences dialog opens. From the left pane, select VirtualBox.

  3. In the Path to VBoxManage field, enter the location where VBoxManage is installed. For example: /usr/bin/VBoxManage.

  4. From the left pane, select VirtualBox VMs, then click New. The VM list shows the VirtualBox VMs you set up earlier.

  5. From the VM list, select the VM that you want to run in GNS3, then click Finish. The VM you selected appears in the center pane. Repeat this step for every VM in the topology that you want to run in GNS3. For the example topology above, the VMs are: Cumulus VX-spine1, Cumulus VX-spine2, Cumulus VX-leaf1 and Cumulus VX-leaf2.

  6. Enable GNS3 to work with the network interfaces of the VirtualBox VMs. Configure the network settings for each VM using the GNS3 interface:

    • Select a VM in the center pane, then click Edit.

    • In the VirtualBox VM configuration dialog, click the Network tab.

    • Increase the number of Adapters to 4.

    • Select the Type to be Paravirtualized Network.

    • Select Allow GNS3 to use any configured VirtualBox adapter.

    • Click OK to save your settings and close the dialog.

          GNS3 overwrites the interface names that are configured in
          VirtualBox; If you want to use the VM in VirtualBox, you might
          want to consider cloning them first.

  7. To connect VMs, select the cable icon from the left pane, then select the VMs to connect directly. To do this, select which network interface you want connected for each VM.

    • Cumulus VX-spine1:
      e1<-> e1 Cumulus VX-leaf1
      e2<->e1 Cumulus VX-leaf2

    • Cumulus VX-spine2:
      e1<->e2 Cumulus VX-leaf1
      e2<->e2 Cumulus VX-leaf2

    • Cumulus VX-leaf1:
      e1<->e1 Cumulus VX-spine1
      e2<->e1 Cumulus VX-spine2
      e3<->e0 PC1 (VPCS)

    • Cumulus VX-leaf2:
      e1<->e2 Cumulus VX-spine1
      e2<->e2 Cumulus VX-spine2
      e3<->e0 PC2 (VPCS)

    e1 in GNS3 corresponds to swp1 in Cumulus VX, e2 to swp2, and so on.

You can also drag and drop virtual PCs (VPCS) and connect them to the Cumulus VX switch.

To open a console to a virtual PC, right click on the VPCS icon and select Console.

In the console, you can configure the IP address and default gateway for the VPCS. For example:


Start all the VMs.

You should be able to ping between the VMs and between the virtual PCs.